Dog Hookworm

Ancylostoma caninum

Dog hookworm is a relatively common parasite in Australia. It can be transferred from dogs, their normal host, to humans. This transfer from animals to humans is termed a ‘zoonotic infection’.

School-age children and adolescents who live in warmer climates are most affected, largely because of their tendency to walk and run barefoot outdoors. Here they may come in contact with the larval worms, if the soil is contaminated with the faeces from an infected dog.

The larval worms penetrate through human skin and migrate through surface tissues causing inflammation (this is known as cutaneous larva migrans). In most cases of human infection with dog hookworm this is as far as they go but in rare cases the immature worm is able to complete its journey through the body and reach the small intestine.

This parasite has been reported as the cause of a condition called eosinophilic enteritis (EE) in some people from north Queensland. It is characterised by inflammation of the small intestine (enteritis) causing abdominal pain with an associated increased level of white blood cells, called eosinophils, in the peripheral blood.

Apparently the worms do not mature in humans as no eggs are passed out in the faeces.

Although human hookworm (Necator americanus) occurs elsewhere in the world it is virtually non-existent in Australia. Only recently has dog hookworm been identified as a problem in humans.

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